Profile Extrusion

Extrusion is a process used to create objects of a fixed cross-sectional profile.

Plastics extrusion is a high volume manufacturing process in which raw plastic material is melted and formed into a continuous profile. Extrusion produces items such as pipe/tubing, weather stripping, fence, deck railing and window frames.

Plastics extrusion commonly uses plastic chips or pellets, which are conveyed into a hopper and gravity fed into the feed screw. The polymer resin is heated to molten state by the combination of heat from heating elements around the barrel and shear heating from the extrusion screw. The screw forces the resin through a die, forming the resin into the desired shape. Depending on the resin and the needed tolerances, that part is then cooled by various methods including water, air or vacuum as itís pulled down the line by the puller. At GaMra every part is checked via in-line laser measurement systems to ensure absolute product quality before being cut, reeled or coiled to the customers required lengths before being checked again and packaged.

Co-Extrusion & Tri-Extrusion:

Co-Extrusion and Tri-Extrusion are the processes of extruding two or more materials through a single die with two or more orifices arranged so that the extrudates merge together into a fused single part. Each material (same or different) is fed from a separate extruder. The benefits of doing so is to provide different finishes, soft and rigid materials or other combinations in one cost effective plastic part. Examples might be weather stripping where there is a soft sealing component mated to a rigid holding member for mounting.

Another example might be the vinyl fencing industry, where co-extrusion is used to tailor the layers based on whether they are exposed to the weather or not. Usually a thin layer of compound that contains expensive weather resistant additives are extruded on the outside while the inside has an additive package that is more suited for impact resistance and structural performance.

The general benefit of the co-extrusion and tri-extrusion process is that every laminate ply imparts a required characteristic property like heat-sealability, stiffness, and impermeability, all of which are impossible to attain by using any single material.